1. Field
The exemplary embodiments of the invention relate to a liquid crystal display (“LCD”).
2. Description of the Related Art
A liquid crystal display (“LCD”) is one of the most widely used flat panel displays. An LCD includes two panels provided with field-generating electrodes such as pixel electrodes and a common electrode and a liquid crystal layer interposed therebetween. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field, which determines the orientation of liquid crystal molecules in the liquid crystal layer to adjust polarization of incident light.
One type of the LCD is a vertical alignment (“VA”)-mode LCD, which aligns liquid crystal molecules such that the longitudinal axes of the liquid crystal molecules are perpendicular to the panels in the absence of an electric field, is spotlighted because of its high contrast ratio and wide reference viewing angle.
The wide reference viewing angle of the VA-mode LCD can be realized by forming a plurality of domains that differ from one another in terms of the orientation of the liquid crystal molecules in one pixel.
To form the plurality of domains in one pixel, there has been suggested a method of forming cutouts such as minute slits in the field-generating electrodes or forming protrusions on the field-generating electrodes. In this method, the plurality of domains may be provided by realigning the liquid crystal molecules perpendicular with respect to fringe fields generated between edges of the cutouts or protrusions, and the field-generating electrodes facing the edges.
Examples of an LCD with means for forming domains include a VA-mode LCD in which means for forming domains is provided on both upper and lower panels and a patternless VA (“PVA”)-mode LCD in which minute patterns are disposed on a lower panel, but not on an upper panel. A display area is divided into a plurality of domains by the means for forming domains, and liquid crystal molecules in each of the domains are tilted mostly in the same direction.
The VA-mode LCD, which aligns liquid crystal molecules such that the long axes of the liquid crystal molecules are perpendicular to the panels in the absence of an electric field, is popular for its high contrast ratio and wide reference viewing angle, which is defined as a viewing angle making a contrast ratio equal to 1:10 or as a limit angle for the inversion of luminance between grayscale levels.
In the VA-mode LCD, the securing of a wide viewing angle is critical. The wide viewing angle of the VA mode LCD can be realized by forming cutouts such as minute slits in the field-generating electrodes or forming protrusions on the field-generating electrodes. The cutouts and the protrusions can determine the tilt direction of liquid crystal molecules, which can be distributed into varying directions to widen the reference viewing angle.